Means for controlling automatic train-stop mechanism from track signaling systems



June 26, 1928. 1,675,250

P. J. CLIFFORD ET AL MEANS FOR CONTROLLING AUTOMATIC TRAIN STOPMECHANISM FROM TRAQK SIGNALING SYSTEMS Original Filed Feb. 19. 1921 g s4mm, 1

11 Ami Inueniom. Patzw'cis J. Clifford, 1072172 Jf. Gjbbg,

171,872? PL qnck b Mai/m J June 26, 1928. 7 1,675,250

. P. J. CLIFFORD ET AL MEANS FOR CONTROLLING OMATIC TRAIN STOP MECHANISMFROM TRACK GNAL SYS TEMS Original Fil Feb. 19. 1921 2 s t -sh n 2 FROMEQU/UZ/NG RESIRVGII? TRIGGER VALVE Batgz'ck J. clg'j fow, Jbhn J1.Gibbs, a

' 291, ,q %%%w mfilzflwi v Inventors.-

Patented June 26, 1928.

* ourrnn STATES PATENT OFFICE.

PATRICK CLIFFORD, OF FALLS, AND JOHN H GIBBS AND HENRY P. LYNCH; OF

SCRANTON, PENNSYLVANIA, ASSIGNORS, BY ASSIGNMENTS, TO TRAIN CON- TROLCORPORATION OF AMERICA, A CORPORATION OF DELAWARE.

MEANS FOR CONTROLLING AUTOMATIC TRAIN-STOP SIGNALING SYSTEMS.

JVIECHANISM FROM TRACK Application filed February 19, 1821, Serial No.446,417. Renewed December 10, 1927.

In application for Letters Patent 01 the United States filed by P. J.Clifford, March 24th, 1919, Serial No. 284,731, is disclosed anautomatic train stop system which is 5 operated by air pressure suppliedthereto through a valve which is operated by a contact device on theengine running over a ramp located alongside the track. Our presentinvention is designed to avoid the use of the l'tllhllfll'ld contactdevice and 1nstead employ electricallyoperated means for controlling theactuation of the air supply valve, which means is capable of combinationwith and control. by signal systems now in use, such as the Hall, sothat a train equipped with the Clifford automatic pneumatically operatedtrain stop system will be controlled from the same electrical apparatuswhich controls the signals.

lt'will be understood, however, that while our invention is describedhereinafter in connection with the Clifford automatic train stop system,its use is not limited to any particular train stop system, nor to anyparticular signaling system like the Hall, and therefore the followingdescription is to be regarded as illustrative of one but not the onlyembodiment of capable.

The drawing in Figure 1. shows a diagram of the invention includinga'portion ot the which our invention standard Hall signaling equipmentin light full lines at the lower part of the diagram, our presentinvention in heavier lines, and a portion of the automatic train stopmechanism on the engine of the Clifford type.

Figure 2 is a detail View of the electrically operated air valve whichsupplies air pres sure for actuating the automatic train stop,mechanism.

F 3 and i show details.

In tlie diagram we. havev shown a single track road but it will beunderstood that the invention may be used on a road of any r number oftracks or on any part thereof gram or below the tracks, excepting thesemaphores.

Parts now to. be described are. located on the engine T he electric airvalve on the engine which controls the supply of air to the automatictrain stop mechanism is shown at EAV, and one object of the presentinvention is 'tooipen this valve to supply air to the automatic trainstop mechanism when thejsemaphore approached by the engineis set atCaution, i. e., 45, or at Danger, i. e., horizontally.

This valve is controlled by a battery VB. It is held closed to cut oil'the air to the automatic train stop mechanism so long as current fromthis battery is flowing through the circuit wires '2 and 4, but when theflow of this current ceases the valve EAV will open and supply air tothe automatic train stop mechanism, and, as a result, the train willbeslowed down or stopped. The flow otcurrcnt through the valve circuit 2,4, is

opened orclosed by governor G driven y controlled by governor contacts 6which are electric motor M. So long as this motor is in operation thecontacts at 6 will be open, because the governor Wlll draw down thecontact bar 6 and the current through the valve circuit 2, at, andbattery VB will be maintained, but when this motor M stops then thecontacts at '6, 6, will'be closed,

establishing acircuit with battery VB oiv lower resistance than. thevalvecircuit 2.4, with the result that current from battery VB will flowthrough circuit, 7, 8, and not through 2 and 4, and the, valve EAV willopen and admit air'to the automatic train stop inechanismjCircuit 7,8,.includes governor controlled contactsQ, as will be de- 1 scribed Ihereinafter.

The motor M is energized from battery MB when relay 10 closes circuit11, 12, which includes battery MB, and it is (lo-energized when relay 10closes circuit 11', 12, which also includes battery MB. Relay 10 is sowound or its armature is positioned close enough to its magnet pole tobe operated by a weak current derived from the track battery through thewheels W of the pony truck and through circuit wires 13, 14. Thiscurrent is too weak to operate relay 10. This latter relay is operatedto close circuit 11, 12, and cut out the motor when current additionalto that sufficient to operate the relay 10 is impressed on circuit 13,14, which happens as presently will be described. The relay 10 isconnected across circuit 13, 14, by branch wires as shown. The circuit11', 12-, is of low resistance as compared with circuit 11, 12, so thatwhen both of these circuits are closedby their relays, current frombattery MB will take the path of least resistance, i. e., throughcircuit 11, 12', and

relay 10, and will not pass through the motor, which consequently willstop.

It willnow be seen from the above descriptionthat when relay 1O alone isclosed, because of the weak current in circuit 13, 14, the motor M willbe driven, contacts 6 will be open, and current from battery VB flowingthrough'circuit 2, 4, will hold the valve EAV closed and prevent airpressure going to the automatic train stop mechanism, and the diagramillustratesthis condition. This condition will exist when the blocksahead of the engine are clear, the only current present in the circuit13, 14, being that derived from the track battery through the pony truckW.

All of the parts above described between valve EAV and the pony truckare carried on the engine. o will now describe other parts constitutinga part of our improve:- mcnt, located along the track and shown in heavylines in the diagram at the portion thereof which lies below the tracks.

Now in order to impress the additional current on the line 13, 14, foroperating relay 10', stopping motor, closing contacts 6,

and thus taking all current from circuit 2, 4, of the valve EAV foropening said valve, we employ a battery which we have called a brakebattery and have indicated at BB. This battery is connected across therails of the track by leads 15. 16, and this circuit includes contacts17 controlled by a cross piece 17' operated by what may be termed thebrake relay and marked BR. This relay we cut into the wire which we havemarked 90 control this being part of the standard equipment of the Hallsignal system.

hen the block ahead of the train is clear, current will be flowing inthiswire, but when the block ahead is set at Caution or Dan: ger, thenno current will be in this wire.

.These conditions are those existing in sig naling systems as will beunderstood by those skilled in the art.

In the former case, i. e., with the block ahead clear, the relay BR willbe energized and contacts 17 will be open and no current will beimpressed on circuit 13 and 14 through the rails and pony truck from thebrake battery BB, and hence only relay 10 will be closed,because onlythe weak current from track battery TB will pass through the circuit 13,14. The air supply valve EAV will therefore remain closed and there willbe no application of the brakes.

Under the other condition mentioned,

however, i. e., when the next or second block ahead is occupied and nocurrent is flowing in 90 control wire, the brake relay BR will bedeenergized, allowing contacts at 17 to close, thus impressing currentfrom brake battery BB upon the circuit '13, 14, through the pony truck,whereupon both relays 10 and 10 will close their contacts and the motorM will cease its revolution, because of the current from battery MBtaking the path of least resistance through 11, 12', and thus excludingthe motor. Contacts at 6,6, will therefore close and current taken fromthe air valve circuit, allowing this to open and the brakes to be set,by supplying air pressure to the automatic train stop mechanism on theengine.

Reverting to the governor controlled contacts 9, we have shown these inFig. 1, and the governor of a diagrammatic form, sufiicient to lead to aclear understanding of the general purpose of this mechanism, whereas,in Fig. 3 we have shown the refinement of this mechanism in order todisclose the particular functions which it performs, and in connectionwith a thermostat control device hereinafter fully described. Thesecontacts 9 are closed by a cross piece 9 connected with a speed governorSG driven from a wheel W of the engine running on the rail, andconnected to the speed governor by a suitable flexible shafting 68. Thisgovernor is set to open the contacts at 9 when the train is runningbelow'the prescribed slow speed, under the full control of the engineer,say, for instance, at 10 miles an hour. When running below this lowspeed, this governor by opening the contacts at 9 eliminates the meansabove described for controlling the train stop mechanism, because withthe circuit 7, 8 open, there can be no shunting of current from the airvalve circuit 2, 4, and this valve will remain closed even though motorM should stop in consequence of a block ahead being occupied. The trainrun ning at this slow speed can be quickly stopped by the engineershould the track remain obstructed.

If, however, the train is running at a higher speed than that consideredto be safe, say, for instance,at any speed above 10 miles an hour, thespeed governor SG will draw down the bar 9' and close contacts 9, 9, and

therefore the air valve circuit will be under the control of theautomatic electrical apparatus above described, and the air valve EAVwill open automatically when the next or second block aheadis'o'ccupied.

There maybe a condition arise where the engineer, after having broughthis train down to the low speed for quick control, he-

comes incapacitated or careless and could not or would notobey a dangersignal, and for taking care of this condition the niechanism shown inFig. 3 is provided, which includes a thermostat T controlling certaincontacts for shunting the circuit 2, etof valve EAV should the traincontinue running for a prescribed time beyond a caution board withoutcontrol by theengineer. Under this condition, the valve EAV would beopened and the train would-be stopped, unless, of course, the trackahead. cleared before the danger point had been reached.

The governor of Fig. 8 includes an insulated portion 20 and a conductingportion 21, roller contacts 9 bear on. the insulating material 20 whenthe train is running a t-the prescribed low quick control speed andtherefore all the control apparatus is cut out and the valve EAV willremain closed, despite any changes in the track signal circuits, and thebrakes will not The applied unless the train continues a prescribed timewith the danger board set against it, whereupon. control will be exertedthrough the.

thermostat T. This thermostat has a coil connected across the circuit .78 and this coil adapted to heat up the U-shaped wire 23 which isprovided with contact 7. This contact, when the U-shaped wire spreads,closes the circuit at contact 8 andprovides a path, for the current, oflow resistance compared with that through the coil 22, this lowresistance path being through the U; shaped wire of the thermostat andthuscurrent from battery VB will be shunted from circuit 2, l, and valve'EAV willopen and the train will be stopped before it reaches conductingportion 21 willthen be between the roller contacts and circuit 7 and Swill be closed at this point ready to be fully established when contactsat 6, 6 close. The movement of the bar 20, 21 downwardly will break thethermostat connection at 24;. and this will remain in this conditionuntil the bar 20, 21 again rises. This is done by collar comesincapacitatedwhile approaching the next boa-rchset at danger, thefollowing action will result:

The continuance of the overcharge current fron'i battery BB impressed oncircuit 13, 14 will maintain contacts 6, 6 closed and the coil ofthermostat T will gradually heat up, because this is nowin circuit Withbattery prescribed time at slow speed,'the thermostat is heating up andthe U-shaped wireis expanding or spreading, its contact will makecircuit at 7", '8, with the result that circuit 7 slice for short'circuiting the. EAV valve During the runningof the train for the and 8Will-110W ,oll'er sufficiently low resistwhich will then open and thebrakes will be I set.

If any wire or electrical connection fails, the EAV valye will open andset the brakes. As one contributing factor to this result we have placeda relay or circuit breaker at 26 in the circuit 2, i of valve EAV, whichreceives current to keep it closed-so long as current is passing throughresistance 27 conneeting across the contacts at 6,6. A high resistancecircuit is thus established, inc-luding circuit wires 7, 8, batteryVB,co1l .26 of thecircuit breaker 26 and resistance coil 27. Thisnormally closed circuit is of high enough resistance to preventshun-ting cur rent entirely from c rcuit .2, {L of valve EAV- andconsequently this valve will remain I closed.

If, however, any ot the circuit wires break or other parts fail betweencontacts 6. 6' and valve EAV, the circuit breaker coil 26' will betie-energized and open circuit 2, 4 of valve BA? with the result thatthis valve will i .open and the brakes will beset. the danger board setagainst 1t. If the track clears before the train travels the prescribedA similar automatic setting action will result from the breaking of anyconnections between the. contacts 6, 6, and the track battery, such asthe circuit 13, 14, or the branch connections to the relay 10, as willbe hereinafter described.

, Virtue EAV. I The valve EAV includes a casing containing a slide va vehaving a port 28 controlling the flow of air pressure from theequalizing "reservoir to the automaticbrake system.

This valve-1s forced normally to the rightto the closed position by aspring '29.

It is m-ovedlto open position by a strong spring 34 upon ole-energizingan electromagnet 30, the armature 31 of which has astem 32 provlded wltha pawl 33. pivoted thereto and engaging a notch in the stem of T and T.

low resistance part. of circuit 7, 8 and re the valve. Theelectro-magnet is energized by circuit 2, 4 and so long as this circuitis maintained the armature will be held towards the right and the valvewill be closed. As soon, however, as circuit 2, 4 is shunted, and theelectro-magnet is de-energized, spring 34, stronger than spring 29, willpull the pawl towards the left and draw the valve into its openposition. As soon as this takes place, however, the pawl will bereleased from the valve rod by its incline 35 riding up on the pin 36and the valve will immediately return to closed position under theaction of its spring 29.

The valve is open only a short space of time, as this will admitsuflicientair pres sure to the system to apply the brakes.

We have provided means whereby after the valve has operated and hasreturned to its closed position under the action of its spring, theelectro magnet will be energizedagain for causing the pawl to re-engagethe valve stem ready foranother application of the brakes.

This means is intended to perform its function whether the brakes areset atfhigh speed or at low speed. It consists of a thermostat T in theshunting circuit 7 8 of the valve battery VB.

lVhentheopening of the valve EAV and its return'to closed ordisconnected position takes place by current assing through this circuit7 and 8 with the train running at high speed, and with the circuitcompleted through the governor at 21, this thermostat will heat up,break the low resistance circuit through this thermostat T whilemaintaining the high resistance circuit here and. permitcurrent frombattery VB to pass through the magnet of the valve EAV and cause thepawl to move to the right and couple up again with the valve stem, readyfor another operation and application of the brakes. The thermostat Tdoes not open the circuit of relay magnet 26, but maintains this circuitthrough the fine Wire coil which forms a part of this thermostat andthis keeps the relay 26' energized. At the same time the coil of thisthermostat will, when heated, break the low resistance and thus preventshorting circuit 2, 4.

The same thing takes place when running at low speed after the brakeshave been setby closing of the circuit 7 8 at the thermostat T. WVhenthis happens, valve circuit 2, 4 is shunted and valve EAV immediatelyopens and then closes and is now in disconnected condition. Current isnow passing through circuit 7, 8, including thermostats The latter willheat up, break store circuit 2, 4 to activity, and cause the valve EAVto be connected up for another application of the brakes. On cooling,ther- -mostat T will close the circuit 7, 8 and thermostat T will openits branch eonnec tion. i

We provide a safety device to secure an application of the brakes, incase the relay 10 or its connections fail.

It will be obvious that, as regards the relay 10, if this fails, or itscircuit is broken, including the track battery branch 13, 14, this relaywill open, the motor M will stop, or if a magnet is used in place of themotor, this will be de-energized and contacts 6, 6 will close to securean application of the brakes.

net of relay 10 or the branch circuit in which it is located fails, thenthe circuit 13,

'14 will be opened at 37 and relay 10 will release its armature andmotor M will stop, and an application of the brakes will take lace.

It will be observed in this connection that our brake controlling meansoperates on the closed circuit system. For instance, the valve EAVremains closed so long as circuit 2, 4 is supplied with current. If thiscircuit breaks, or if the circuit 7, 8, breaks, then the valve EAV willbe opened, because the breaking of circuit 7 8, will result in breakingof the valve circuit 2, 4, on account of the opening of the circuitbreaker with which the latter circuit is provided, as above described.

Also if the closed track battery circuit 13, 14 breaks, contacts 6, 6will close as a consequence of the stopping of the motor, and a brakeapplication will result, or if the relay 10" or the branch circuit inwhich it is located fail, the circuit 13, 14 will be opened and thus abrake application will take place We trace the circuits in the roadsidesigby reason of the stoppage of the motor M naling system and relay BRunder diflier ent conditions as follows:

Case 1. Train on block #5 only.

Both 4 ohm relays on track #5 deener- 'gized. Circuit through relay BRremains open at the contact a. L

Case 2, Train on block #3 only. Both 4 ohm relays on track #3deenergized.

Circuit: through relay BR, through contact a, through contact 0, commonwired,

contact 6, back to relay BR, which means that relay BR isshort-circuited on itself, i. e. deenergized.

Game 5. N 0 train on any block.

All 4: ohm relays are energized.

Circuit: relay BR, contact 0, conductor f, contact 9, 50 ohm relay,conductor it and contact 7a which is broken, relay BR deenergized.

Case 4. Train on block #1.

4 ohm relay on track #1 are deenergized. Circuit: relay BR, contact 6,conductor 7", contact 9, 50 ohm relay, conductor h, contact k, to commonwire d, conductor m, minus of battery #5-7, plus of battery #57, contacta, 45 connection of'block #5, contact 0, 800 ohm relay, conductor 5,contact a, and back to relay BR. i

It Will be understood that the apparatus above described is illustrativeof our invention and is not to be considered in a restrictive sense, andchanges can be made 'without departing from the principles involved.

It will be understood that while we have means supplied with currentfrom said track battery when the line is clear for 1n21111tt111- ingsaid device against operation, a brake battery in the signal system forsupplying additional current when a caution or danger signal is setagainst the train, said additional current controlling said means tocause the operation of the said device to set the brakes, substantiallyas described.

2. In train stop apparatus, a device for controlling'the setting of thebrakes, a trackway system including a track battery, a relay arranged inone of the trackwaywires, a brake battery controlled by said relay tosupply additional current when the relay closes consequent upon' theabsence of current in the said wire, and means controlled by the trackbattery current and by the additional current from the brake battery forcontrollingthe operation of the said device.

3. In train stop mechanism tllOCOlllblllfition of a device on thevehicle to control the setting of the brakes, atrackway system includinga track battery, a pair otrela ys on the'vehicle' and in circuit withthe track battery, one adapted to be operated by current in the trackbattery circuit, and the other by additional current impressed on thetrack battery circuit, a brake battery for impressing the additionalcurrent on the the for controlling the brake battery, means controlledby the said pair of relays for maintaining the said device inoperativewhile the weak current of the track battery is flowing and for operatingthe said de vice when the additional current is flowing, substantiallyas described.

4:. In combination, automatic train stop mechanism, a valve forsupplying air there to for setting the brakes, an electric trackwaysystem, electrical apparatus on the vehicle controlled by the conditionsin the trackwaysystem for maintaining said valve closed when the trackis clear and for opening said valve for 'the inlet or air pressure tothe brakejsystem when a caution or danger signal is set, a speedgoverned device controlling a contact of said electrical apparatus toprevent operation of the valve when the train is running at a prescribedreduced speed, and means for restoring the function of the saidelectrical apparatus to operate said valve for setting the brakes shouldthe train continue at the reduced speed for a prescribed interval priorto a change in the signals, said electrical apparatus on the vehicleincluding relay means in a conductor receiving current from the tractionrail sys tem due to the drop in potential between the points of contactof said conductor with said rail system, substantially, as described.

5; In' combination intrain stop appa for closing said circuit, saidrelay being an,

the track battery circuit of the signaling system, a second relay'insaid system open able when additional current is impressed on the trackbattery circuit, a circuit for shunting the ClQCtllC device batteryfron'r the electric device controlled by said second relay, a brakebattery for impressing the additional current on the track batterycircuit, and a relay in the signal system for controlling thebrakebattery, substantially as described.

6. In combination, automatic train stop mechanism, a valve for supplyingair thereto for setting the brakes, an electric trackway system,electrical apparatus on the vehicle controlled by the conditions in thetrackway system for maintaining said valve closed when the track isclear and for opening said valve for the inlet of air pressure to thebrake system when a caution or danger signal is speed governorcontrolling contacts for eliminating the function of the said elecsetagainst the train, a

trical apparatus to prevent operation of the valve when the train isrunning at a prescribed reduced speed, and means for restoring thefunction of the said electrical apparatus to operate the said valve forsetting the brakes should the train continue at the reduced speed for aprescribed time prior to a change in the signals, substantially asdescribed.

7. In connection with the features of claim 6, the restoring meanstherein mentioned consisting of a thermostat having a resistance coil,which, when heated by the continued flow of the current therethroughwhile the train is running at reduced speed in response to a caution ordanger signal, will close the circuit previously opened by said governorto effect the opening of the valve and the setting of the brakes.

S. In combination with an automatic train stop system, including a valvefor admitting air pressure into the system for applying the brakes, asignal system along the tracks for indicating when the track is clear orobstructed, said system including a control wire and a track battery,means controlled by the track battery when current is in the 90 controlwire consequent upon a clear track for maintaining the air valve closed,and means rendered effective when no current is present in said controlWire consequent upon the track being obstructed, for furnishing currentadditional to that furnished by the track battery for causing said firstmentioned means to open the air valve, substantially as described.

9. In combination with an automatic air pressure operated train brakesystem, a valve for supplying air pressure thereto, a battery, circuitconnections, and means controlled thereby for maintaining the valve shutso long as said circuit is supplied with current, a signaling system toindicate to thekengineer caution, danger or a clear track, and

means actuated by and in response to changes in the conditions thereoffor shunting said circuit for the opening of the air pressure valve whena caution or danger board is set against the train, said signalingsystem connecting up with said last mentioned means through the ordinaryt 'ack rails, so that said means is subject to open tion at all times,substantially as described.

10. In combination with an automatic train brake system, an air valvefor supplying air pressure thereto for setting the' brakes, a battery,and electro-magnetic means in a normally closed circuit for allowing theair valve to remain closed as long as the said circuit is closed, acircuit including said battery to shunt current from the normally closedcircuit first mentioned, means for closing said shunting circuit, acircuit breaker in the normally closed circuit energized by current inthe shunting circuit to maintain said closed circuit and to open thenormally closed circuit upon failure'of the shunting circuit'to therebycause the opening of the valve and the setting of the brakes. a V

11. In combination, brake setting mechanism, an air valve controllingthe admission of air thereto for setting the brakes, a signaling systemfor setting signals along the track against the engineer, said signalingsystem including a. track battery, a branch circuit on theengineconnected with the track battery circuit throughthe engine andrails, a relay in said branch circuit, a battery and circuit controlledby the said relay, means in said relay circuit for controlling thevalve, a second relay for shunting the relay circuit, a circuit breakerin the branch circuit of the first relay, the magnet of which is in thebranch of the second relay, whereby if said second relay fails, thefirst relay will open and the brakes will be set by the opening of theair valve, substantially as described. i

12. In train stop systems, an air valve for controlling air pressure tothe brake mecha-v nism for setting the brakes, a signaling system torsetting signals against the eng neer,

including a track battery, a relay on the train in a branch of the trackbattery, means energized by the relay circuit, means controlled therebyfor maintaining the air valve closed so long as said relay circuit ismaintained, a brake battery alongside the track for impressingadditional current on the track battery circuit and its branch on thetrain, a

relay across the branch circuit energized by the additional currentimpressed on said branch circuit for shunting the battery of the relaycircuit first mentioned, and a circuit breaker for the first relaycontrolled by the circuit of the second relay whereby it either relayfails the air valve will open to apply the brakes, substantially asdescribed.

13. In combination with automatic train stop apparatus, a valve foradmitting air pressure for operating said apparatus for setting thebrakes, a battery, electromagnetic means in circuit with the battery,said valve being in closed position when the said battery circuit isclosed, a secondcircuit including said battery which when closed shuntsthe current from the first'mentioned circuit to thereby cause theopening of the valve and the setting of the brakes, and thermostaticmeans in the second circuit for breaking the same to thereby renderactive the first circuit for placing the valve in condition for anotherapplication of the brakes, all the above mentioned parts being on thetrain.

14. In combination with automatic train stop apparatus, a valve foradmitting air pressure for operating said apparatus for setting thebrakes, a battery, electro-magnetic tery circuit is closed, a secondcircuit in-.

cluding said battery which when closed shunts the current from the firstmentioned circuit to thereby cause the opening oi? the valve and thesetting of the brakes, and thermostatic means in the second circuit forbreaking the same to thereby render active the first circuit for placingthe valve in condition for another application of the brakes, all theabove mentioned parts being on the train, a signaling system for settingsignals along the track against the engineer, contacts normally open insaid shunting circuit, and means on the train for closing said contacts,said means being controlled from the signaling system according tochanges therein, due to the positions of the signal boards,substantially as described.

15. In combination with automatic train stop mechanism, an air valve foradmitting air pressure thereto, comprising a casing, a

valve member, a spring for moving the valve member to closed position, astronger spring for moving the valve member to open position, adetachable connection between the strong spring and the valve member, anelectro-magnet and armature for coupling said strong spring to the valveand for opposing the force of the strong spring, a battery in circuitwith the electro-magnet and means for controlling said circuit, saidstrong spring when the magnet is de-energized opening the valve,substantially as de scribed.

16. In combination with automatic train stop mechanism, an air valve foradmitting air pressure thereto, comprising a casing, a valve member, aspring for moving the valve member to closed position, a-stronger springfor moving the valve member to open position, a detachable connectionbetween the strong spring and the valve member, an electro-magnet andarmature for coupling said strong spring to the valve and for opposingthe "force of the strong spring, a battery in circuit with theelectro-magnet and means for controlling said circuit, said strongspring when the magnet is (lo-energized opening the valve, and means foruncoupling the valve from the strong spring when it has been opened, tobe returned by the spring first mentioned to closed position.

17. In combination with automatic train stop mechanism, an air valve, anelectromagnet and armature, a rod connected with the armature, a pawl onthe rod to couple with the valve stem, a spring for moving the valve toclosed position when the pawl is uncoupled, a strong spring connected tothe rod for moving the rod and the coupled valve to open position whenthe electro-magnet is deenergizcd, and means for uncoupling the pawlfrom the valve when the latter reaches its open position, so that thevalve.- can re turnto closed position, thesa'id electro-n'iag not whenagain. energized moving the pawl carrying rod to engage withthe valveand set the strong spring-tor another opening movement of thevalve,substantially as described. y r

18. In combination with automatic train stop mechanism, an air valve foradmitting air pressure thereto for setting the brakes, means foroperating said valve. to open posis tion, an elcctro-magnet which whenenergized sets said. operating means ready to act and couples the samewith the air valve detachably, and when de-energized permits saidoperating mechanism to open the valve,

means for uncouplingthe air valve from its operating means when itreaches its open position, said valve when uncoupled resuming its closedposition, substantially as described.

19. In train stop apparatus a device for controlling the operation ofthe brakes, a

trackway system. including a track battery,

means supplied with current from said track battery when the line isclear for maintain ing said device against operation, a brake battery inthe trackway system for supplying additional current when a caution ordanger signal is set against the train, said additional currentcontrolling said means to,

cause the operation of the said device to set the brakes, substantiallyas described.

20. In combination, means on the vehicle for automatically applying thebrakes, elec tric controlling means in part on the vehicle and in parton the roadway for automatically operating the said brake applying meansfor setting the brakes when the train runs into a caution or dangerblock at high speed, and to defer said brake setting when the train isrunning at a reduced speed until after a prescribed interval haselapsed, said vehicle carried means and said roadway means being inconductive circuit through the track-Way rails and parts on the vehic-le constantly in contact therewith, substantially as described. v

21. In combination, means on the vehicle for automatically applying thebrakes, electric controlling means in part on the vehicle and in part onthe roadway for automatically operating the said brake applying meansfor setting the brakes when the train runs into acaution or danger blockat high speed, and to deter said brake setting when the train is runningat a reduced speed until attcr a prescribed interval has elapsed, saidcontrolling means acting to prevent a brake application should theconditions in the block change to clear before the said prescribedinterval elapses, said vehicle carried means and said roadway meansbeing in conductive circuit through the track-Way rails and parts on thevehicle in constant contact plication means on the vehicle, controllingmeans therefor including a governor and a timing device on the vehicleand trackway devices, said brake application means being operated to setthe brakes at the prescribed time when the train is running at highspeed and said brake setting being deferred when the train is running ata reduced speed, said track-way devices and timing device being in aconductive circuit through the track-way rails and parts on the vehiclein constant contact therewith, substantially as described.

23. Automatic train stop mechanism including means on the vehicle forautomatically applying the brakes, an electrical track- Way system inconductive circuit with the means on the vehicle, through the track-wayrails and parts on the vehicle in constant contact therewith, thevehicle carried means being operable to apply thebrakes automati' callyat different times according to the speed of the train, i. e. at or nearthe time of entering the block at high speed and after a prescribedinterval of time has elapse; at a reduced speed, substantially asdescribed.

In testimony whereof we afiix our signatures.

PATRICK J. CLIFFORD.

